The Takatika Grit is a geologic formation in Chatham Islands, New Zealand. It preserves fossils dating back to the Paleocene period, although it also preserves disturbed and re-worked Maastrichtian and Campanian microfossils and tetrapod fossils. A 2017 study found that it dated to late Early to Mid Paleocene on the basis of dinoflagellates. It has been subdivided into two informal units, a lower phosphatic unit containing bones and nodular phosphatic layers, and an upper unit with abundant sponge remains and siliceous microfossils.[1]

Takatika Grit
Stratigraphic range: Late Early to Mid Paleocene 63–60 Ma
TypeFormation
Unit ofTioriori Group
Sub-unitsTaP1, TaP2, TaS1, TaS2
UnderliesTutuiri Greensand
OverliesChatham Schist
Thickness5.7 metres exposed
Lithology
PrimaryGrit, sandstone
Location
Region Chatham Islands (Chatham Island)
Country New Zealand

Description

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The two informal units are further subdivided into two units each, the lower is divided into the lower TaP1 which consists of "poorly sorted, phosphatized grit with abundant phosphorite nodules and bones" and the upper TaP2 which consists of "nodular bedded sandstone and grit". The upper biosiliceous unit is divided into the lower TaS1, which is heavily bioturbated, and the upper TaS2 "characterized by parallel laminations and sinusoidal ripples".[1]

Paleofauna

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Paleofauna of the Takatika Grit
Genus Species Location Stratigraphic position Abundance Notes
Astrophorida indet.[2] indeterminate Tioriori Only fragmentary spicules are known
Auloplax? (Dactylocalycidae indet.?)[2] A? sp. Tioriori Hexactinellid sponge
Bacillariophyceae indet.[3] Indeterminate Tioriori Diatoms from the Takatika Grit date back to the Danian and Campanian
Chlamydoselachus[4] Indeterminate Tioriori
Dinoflagellata indet.[3] Indeterminate Tioriori Dinoflagellates from the Takatika Grit date back to the Danian and Campanian
Edaphodon E. kawai Tioriori
Elasmosauridae indet.[2] indeterminate Tioriori lower (?) Takatika Grit Almost certainly reworked from older sediments.
Eotretochone[2] E. australis Tioriori Hexactinellid sponge
Euretidae indet.[2] Indeterminate Tioriori
Kupoupou[5] K. stilwelli Tioriori Penguin
Gastropoda indet.[6] Indeterminate Tioriori
Lithistida indet.[2] Indeterminate Tioriori Known from scarce weathered fragments
Lycopodiopsida indet.[7] Indeterminate Tioriori
Mosasauridae indet.[2] Indeterminate Tioriori lower (?) Takatika Grit Almost certainly reworked from older sediments.
Radiolaria indet.[3] Indeterminate Tioriori Radiolarians from the Takatika Grit date back to the Danian and Campanian
Pararete[2] P. sp. Tioriori Hexactinellid sponge

Theropoda indet.[7]

Indeterminate

Tioriori lower (?) Takatika Grit Vertebral centrum, tibia head, proximal pedal phalanx, manual ungual, proximal manual phalanx Initially suggested to represent evidence of Palaeogene dinosaurs.[8][9][7][10] Almost certainly reworked from older sediments.[1]
Tretodictyiidae indet.[2] Indeterminate Tioriori

See also

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References

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  1. ^ a b c Hollis, Christopher J.; Stickley, Catherine E.; Bijl, Peter K.; Schiøler, Poul; Clowes, Christopher D.; Li, Xun; Campbell, Hamish (2017-07-03). "The age of the Takatika Grit, Chatham Islands, New Zealand". Alcheringa: An Australasian Journal of Palaeontology. 41 (3): 383–396. doi:10.1080/03115518.2017.1296189. ISSN 0311-5518. S2CID 133527355.
  2. ^ a b c d e f g h i Consoli, Christopher P.; Stilwell, Jeffrey D. (August 2009). "Late Cretaceous marine reptiles (Elasmosauridae and Mosasauridae) of the Chatham Islands, New Zealand". Cretaceous Research. 30 (4): 991–999. doi:10.1016/j.cretres.2009.02.009.
  3. ^ a b c Hollis, C.J, Stickley, C.E., Bijl, P.K., Schiøler, P., Clowes, C.D., Li, X, Campbell, H. March 2017. The age of the Takatika Grit, Chatham Islands, New Zealand. Alcheringa 41, xxx–xxx. ISSN 0311-5518.
  4. ^ Consoli, Christopher P. (2008-06-12). "A rare Danian (early Paleocene) Chlamydoselachus (Chondrichthyes: Elasmobranchii) from the Takatika Grit, Chatham Islands, New Zealand". Journal of Vertebrate Paleontology. 28 (2): 285–290. doi:10.1671/0272-4634(2008)28[285:ARDEPC]2.0.CO;2. ISSN 0272-4634. S2CID 130714866.
  5. ^ Jacob C. Blokland, Catherine M. Reid, Trevor H. Worthy, Alan J.D. Tennyson, Julia A. Clarke, and R. Paul Scofield. 2019. Chatham Island Paleocene Fossils provide insight into the Palaeobiology, Evolution, and Diversity of early Penguins (Aves, Sphenisciformes). Palaeontologia Electronica. 22.3.78; 1-92.
  6. ^ Stilwell, Jeffrey D. (March 2007). "First record of Late Cretaceous Gastropoda (Mollusca) from the Takatika Grit, Chatham Islands, Southwest Pacific". New Zealand Journal of Geology and Geophysics. 50 (1): 21–25. doi:10.1080/00288300709509816. ISSN 0028-8306.
  7. ^ a b c Stilwell, J.D.; Consoli, C.P.; Sutherland, R.; Salisbury, S.; Rich, T.H.; Vickers-Rich, P.A.; Currie, P.J.; Wilson, G.J. (2006). "Dinosaur sanctuary on the Chatham Islands, Southwest Pacific: First record of theropods from the K–T boundary Takatika Grit". Palaeogeography, Palaeoclimatology, Palaeoecology. 230 (4): 243–250. doi:10.1016/j.palaeo.2005.07.017.
  8. ^ Fordyce, R. E. 2006. New light on New Zealand Mesozoic reptiles. Geological Society of New Zealand newsletter 140: 6-15.
  9. ^ Haw, D. 2002. The discovery of fossils in Mangahouanga Stream. Geological Society of New Zealand newsletter 129: 13-14.
  10. ^ Fordyce, R. E. 2003. Fossils and the history of life. Pp 35-64 in Darby, J. T., Fordyce, R. E., Mark, A. F., Probert, P. K., & Townsend, C. R. (eds), The natural history of southern New Zealand. University of Otago Press, Dunedin. 387 p.